Better binary defaults

Signed-off-by: jolheiser <john.olheiser@gmail.com>

README.md

@@ -4,6 +4,10 @@
 
 **NOTE:** This URL may not remain permanent, it is simply usable at the time of writing this library.
 
+## Installation
+
+`go install git.jojodev.com/golang/dl/cmd/godl@main`
+
 ## License
 
 [MIT](LICENSE)

cmd/godl/godl.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"context"
+	"errors"
 	"flag"
 	"fmt"
 	"io"
@@ -18,8 +19,8 @@ import (
 )
 
 func main() {
+	downloadFlag := flag.Bool("download", false, "Download latest Go")
 	installFlag := flag.Bool("install", false, "Install/Update Go (Linux only)")
-	versionFlag := flag.Bool("version", false, "Only print version")
 	outFlag := flag.String("out", ".", "Where to put the downloaded file")
 	flag.Parse()
 
@@ -29,63 +30,47 @@ func main() {
 		return
 	}
 
-	if *versionFlag {
+	if !*downloadFlag && !*installFlag {
-		fmt.Println(latest.Version)
+		ver, err := goVersion()
-		return
-	}
-
-	outPath, err := download(latest.Filename, *outFlag)
 		if err != nil {
 			fmt.Println(err)
 			return
 		}
+		fmt.Printf("Current: %sLatest: %s\n", ver, latest.Version)
+		return
+	}
+
+	outPath := filepath.Join(*outFlag, latest.Filename)
+
+	if *downloadFlag {
+		if err := download(latest.Filename, outPath); err != nil {
+			fmt.Println(err)
+			return
+		}
 		fmt.Println(outPath)
-
-	if !*installFlag {
-		return
 	}
 
-	if !strings.EqualFold(runtime.GOOS, "linux") {
+	if *installFlag {
-		fmt.Println("Install option is only for Linux. Mac and Windows users should run the downloaded installer.")
+		if err := install(outPath); err != nil {
+			fmt.Println(err)
 			return
 		}
-
+		ver, err := goVersion()
-	if os.Geteuid() != 0 {
+		if err != nil {
-		fmt.Println(`This command must be run as root to perform the install.
+			fmt.Println(err)
-Alternatively, you can run the following command manually, which is taken from https://golang.org/doc/install#install
-
-rm -rf /usr/local/go && tar -C /usr/local -xzf ` + outPath)
 			return
 		}
-
+		fmt.Printf("Successfully installed: %s\n", ver)
-	fmt.Println("removing local installation")
-	rm := exec.Command("rm", "-rf", "/usr/local/go")
-	if err := rm.Run(); err != nil {
-		fmt.Printf("could not remove local go installation: %v\n", err)
-		return
-	}
-
-	fmt.Println("extracting new installation")
-	tar := exec.Command("tar", "-C", "/usr/local", "-xzf", outPath)
-	if err := tar.Run(); err != nil {
-		fmt.Printf("could not extract new installation: %v\n", err)
-		return
-	}
-
-	rmDl := exec.Command("rm", outPath)
-	if err := rmDl.Run(); err != nil {
-		fmt.Printf("could not remove downloaded file: %v\n", err)
-		return
 	}
+}
 
+func goVersion() (string, error) {
 	goVersion := exec.Command("/usr/local/go/bin/go", "version")
 	out, err := goVersion.Output()
 	if err != nil {
-		fmt.Printf("could not check go version: %v\n", err)
+		return "", fmt.Errorf("could not check go version: %v", err)
-		return
 	}
-
+	return string(out), nil
-	fmt.Printf("Successfully installed: %s\n", string(out))
 }
 
 func latestVersion() (*dl.File, error) {
@@ -111,23 +96,22 @@ func latestVersion() (*dl.File, error) {
 	return &version, nil
 }
 
-func download(filename, out string) (string, error) {
+func download(filename, outPath string) error {
-	outPath := filepath.Join(out, filename)
 	outFile, err := os.Create(outPath)
 	if err != nil {
-		return outPath, fmt.Errorf("could not create file for download: %v", err)
+		return fmt.Errorf("could not create file for download: %v", err)
 	}
 	defer outFile.Close()
 
 	req, err := http.NewRequest(http.MethodGet, fmt.Sprintf("https://golang.org/dl/%s", filename), nil)
 	if err != nil {
-		return outPath, fmt.Errorf("could not create request: %v", err)
+		return fmt.Errorf("could not create request: %v", err)
 	}
 	req.Header.Set("User-Agent", "git.jojodev.com/golang/dl/cmd/godl")
 
 	res, err := http.DefaultClient.Do(req)
 	if err != nil {
-		return outPath, fmt.Errorf("could not download file: %v", err)
+		return fmt.Errorf("could not download file: %v", err)
 	}
 	defer res.Body.Close()
 
@@ -137,8 +121,40 @@ func download(filename, out string) (string, error) {
 	)
 
 	if _, err := io.Copy(io.MultiWriter(outFile, bar), res.Body); err != nil {
-		return outPath, err
+		return err
 	}
 
-	return outPath, nil
+	return nil
+}
+
+func install(outPath string) error {
+	if !strings.EqualFold(runtime.GOOS, "linux") {
+		return errors.New("Install option is only for Linux. Mac and Windows users should run the downloaded installer.")
+	}
+
+	if os.Geteuid() != 0 {
+		return fmt.Errorf(`This command must be run as root to perform the install.
+Alternatively, you can run the following command manually, which is taken from https://golang.org/doc/install#install
+
+rm -rf /usr/local/go && tar -C /usr/local -xzf ` + outPath)
+	}
+
+	fmt.Println("removing local installation")
+	rm := exec.Command("rm", "-rf", "/usr/local/go")
+	if err := rm.Run(); err != nil {
+		return fmt.Errorf("could not remove local go installation: %v", err)
+	}
+
+	fmt.Println("extracting new installation")
+	tar := exec.Command("tar", "-C", "/usr/local", "-xzf", outPath)
+	if err := tar.Run(); err != nil {
+		return fmt.Errorf("could not extract new installation: %v", err)
+	}
+
+	rmDl := exec.Command("rm", outPath)
+	if err := rmDl.Run(); err != nil {
+		return fmt.Errorf("could not remove downloaded file: %v", err)
+	}
+
+	return nil
 }